With the development of display technologies, an overall screen with a high screen occupation ratio, an ultra-narrow edge frame, etc., can significantly improve a visual effect for a watcher, compared with a general display screen, and thus has been widely concerned. In order to display throughout the screen of a mobile phone as illustrated in FIG. 1, for example, four corners of a display region A are abnormally shaped regions C in which sub-pixels Px are arranged in a step-like distribution, thus resulting in a significant saw-tooth phenomenon at the edge of an image being displayed.